Brain Wave Monitor

Hello all. I apologise for posting this to multiple groups but I believe
any/all of you could help me.
I'm studying states of consciousness and the brain, and would like to build
a brain wave monitor. THis should be a fairly simple but sensitive radio
receiver but I can not find any information about the frequencies emmited
by the brain during different states - alpha, gamma etc.
After studying the frequencies emmited during certain activities I hope to
be able to stimulate the brain using EM waves during sleep to induce
different types of dreams.
If anyone has any thoughts on the subject, or think they could help please
reply to this post or by E-Mail if you think the subject matter is not
appropriate to the group.
Thanks
--
Jonathan Baker
jon at marzipan.demon.co.uk